Adjustable chair back



June 3, 1947. A. E. JONES 2,421,702

ADJUSTABLE CHAIR BACK Filed Nov. 13, 1944 2 Sheets-Sheet 1 Z5 hZ/M r 4% 1 06/2721 Z15 23 Milli 275465 June 3, 1947. E, JONES 2,421,702

ADJUSTABLE CHAIR BACK Filed Nov. 15, 1944 2 Sheets-Sheet 2 19 gr 6 J98 7 M l 2 31 '///%M 4 8 27 4 9 50 39 T7 W 35 n 4 @5 r 3.5 5% Ja e/#01 5 A. fif/zwffinas ZK. f fi M Patented June 3, 1947 ADJUSTABLE CHAIR BACK Arthur E. Jones, Elkhart, Ind., assignor to Posture Research Corporation, Elkhart, Ind., a corporation of Indiana Application November 13, 1944, Serial No. 563,192

9 Claims. 1

This invention relates to improvements in chairs and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

The invention is more especially concerned with a substantially all metal bench and desk worker's chair, usually subjected to hard usage.

One of the objects of the present invention is to provide in a chair of this kind, simple, efficient means whereby the back rest of the chair may be readily raised or lowered and moved forwardly and rearwardly to adjust the same into that position most comfortable for the occupant of the chair.

Another object of the invention is to provide in a chair of this kind a structure permitting adjustment of the back rest into the desired position with respect to the seat without the provision of slots in the parts employed so that the structure is strong and rigid and will not warp out of shape.

Also. it is an object of the invention to provide in a chair of this kind, a very strong and rigid base and with respect to which the seat spindle has adjustment and may be positively secured in the adjusted position.

The above mentioned objects of the invention, along with others will more fully appear as the specification proceeds.

In the drawings:

Fig. l is a view in side elevation of the improved chair embodying the preferred form of the invention.

Fig. 2 is a horizontal sectional view through an upper part of the base of the chair, on the scale of Fig. 1, as taken on the line 2-2 thereof.

Figs. 3 and 4 are horizontal sectional views through parts of the base of the chair as taken on the lines 3-3 and 4-4 respectively and on a scale enlarged over that of Fig. 1.

Fig. 5 is a horizontal sectional view through parts of the chair as taken on the line 5-5 and on a scale enlarged over that of Fig. 1.

Fig. 6 is a, longitudinal vertical detail sectional view through a part of the chair, as taken on the line 6-6 and on a scale enlarged over that of Fig. 5.

Fig. '1 is a vertical detail sectional view as taken on the line 11 and on the scale of Fig. 6.

Fig. 8 is a. horizontal detail sectional view as taken on the line 6-8 and on the scale of Fig. 6.

Fig. 9 is a view in elevation of one of a pair of friction shoes embodied in the chair on the scale of Fig. 6.

Fig. 10 is a view in elevation of one of a pair of supporting members for an associated shoe shown in and on the scale of Fig. 9.

Referring now in detail to that embodiment of the invention illustrated in the drawings, the improved chair generally includes an all metal multi-leg base l5, a seat 16 mounted on a spider l1 that carries a seat supporting spindle l8 for vertical adjustment relative to the base and a supporting member l9, which carries a back rest 20 at its upper end. Said member l9, at its lower end, is so engaged in a part of the spider, rearwardly of the seat, as to be capable of adjustment to dispose the back rest at different elevation and at different positions forwardly and rearwardly relative to the seat.

The base comprises four generally upright. legs 2l--2l preferably .made of angle'bars' and arranged in fairly close grouped relation at their upper ends and extending downwardly and outwardly therefrom, toward their bottom end where they are outwardly splayed and flattened to form feet 22 having a. spread that imparts good stability to the base. In each flattened foot is a depressed dome 23 for engagement with the supporting surface for the chair as a whole.

The upper end of the legs are disposed in and welded to a cap piece 24 (see Fig. 1) and below the same, within the legs, is a square spider plate 25, the corners of which are disposed within the corners of the angle bar legs and are welded thereto. The legs are further secured together below the spider plate by stiifener rods 26-26 suitably welded to the inside of the angle bar legs. These rods are best shown in Figs. 1 and 4. The structure described provides a strong, rigid and stable base capable of withstanding h'ard usage without distortion.

The seat 16, as shown, includes a generally rectangular wooden body l6a with suitable upholstery I61) thereon, as best appears in 6. The seat is preferably narrower at the rear than at the front, as best appears in Fig. 5.

The spider I1 is preferably made of a length of relatively stiff strip metal stock bent into substantially a U-shape to include vertically edgewise disposed side bars 21-21. These bars extend beyond the rear edge of the seat and the rear ends thereof are connected together by an end bar 28. The front ends of the bars 21-21 are directed outwardly and forwardly at suitable angles, their ends 2923 being twisted into a horizontal plane for attachmentto the underside of the seat base l6a by bolts 30-36. The side bars 21-21 are also connected by a cross bar 3| disposed in the plane of the rear edge of the seat.

The front end of the parallel parts of the bars 21-21 are also fixed to and connected together by a plate 32 (see Fig. 5). The upper end of the spindle |8, before mentioned, fits and is operatively secured in an opening in said plate against relative movement.

The bars 21-21 are disposed upon opposite sides of the front to rear medial line of the seat and the spindle I8 is disposed on said line closer to the rear edge of the seat than to the front edge thereof, as best appears in Fig. 5. On the upper edges of the bars 21-21 forwardly of the cross bar 3| a plate 33 is welded. The central rear margin of the seat base |6a rests on this plate and is secured thereto by a bolt and associated nut 34. Parts of the bars 21-21, along with the end and cross bars 28 and 3| respectively define an opening to the rear of the seat and which opening is indicated at 35 in Fig. 8, the front end of said opening being disposed in the plane of the rear edge of the seat.

The spindle l8, which is herein shown as cylindrical, is provided with a longitudinal groove in which a spline |8a is fixed in any suitable manner and this spindle and its spline extend through correspondingly shaped openings in the cap 24 and spider respectively. When the spindle is in place relative to the base, the spline |8a is directed radially of the spindle, and is disposed in a plane passing through the corner of the angle bar of one of the legs 2| as best appears in Figs. 1 and 2. A threaded bushing 36 is fixed in a part of said corner of said one of said legs between the cap 24 and plate 25 and this bushing receives the threaded end of a T-shaped screw 31, the inner end thereof being adapted for clamping engagement with the spline of the spindle to hold the same in the desired adjusted vertical position relative to the base. By loosening this screw the spindle may be moved upwardly and downwardly in the base to position the seat at the desired elevation and in which position it is held by tightening the screw 31.

The backrest supporting member I9 is made from a length of fiat strip metallic stock bent into the form of an elongated U having sides 38-38 so laterally spaced as to fit between those parts of the bars 21-21 of the spider forming the sides of the opening 35. The sides 38-38 of said member l9 are connected together at the lower end by a part 39 (see Fig. 7) and the upper ends of said sides splay laterally and extend forwardly to receive the ears 4!] (see Fig. 1) attached to the rear side of the back rest 20 and by which said back rest is attached to the supporting member 9 for a limited rocking movement better to accommodate the back of the occupant.

4|-4| indicate shoes, one for each side 38-38 of the back rest supporting member l9 and one of which shoes is shown in elevation in Fig. 9. Each shoe is provided with a longitudinal groove 42 in its outer surface that is adapted. to receive a part of the associated side 38 of the. member l9. This groove has a depth less than the thickness of the associated side so that the outer surface of said side is spaced laterally outward beyond the outer surface of the shoe. This arrangement of parts is best shown in Figs. '7 and 8.

Centrally and on the inner surface of each shoe is a stud 43 and also on said surface concentric with said stud are top and bottom rosette teeth 44.

Associated with the inner surface of each shoe is a supporting member 45, in the form of a disc having parts cut away to form parallel straight ends 48-4811 respectively, s0 spaced as to fit between the bars 28 and 3| of the spider |1. On the outer arcuate portion of each member 45 are rosette teeth 41 for cooperative engagement with the rosette teeth 44 of the associated shoe. Centrally of each member 45 is an opening 48 to receive the stud 43 of the associated shoe and on the inner surface of each member and extending between the ends 46-4611 thereof is a. groove 49 which is deeper toward the end 46 than it is toward the end 48a as is obvious from Fig. 8.

58 indicates a wedge block that engages at its tapered sides in the grooves 49-49 of the members 45-45. A T-shaped screw 5| has threaded engagement longitudinally of the wedge block and its front end has a swivelled engagement in the cross bar 3|. This screw has rotative engagement in the cross bar 28 and includes a right angled handle beyond said bar and by which said screw may be turned in either direction.

Between the inner surface of each shoe 4| and the outer surface of the associated supporting member 45 is a spider-like spring element 52 which serves to urge the member 45 away from its associated shoe 4|. Each spring 52 has a central hole to permit the passage of the stud 43 therethrough.

It is to be noted that the screw 5| supports the wedge block 58 and this supports the members 45-45 by reason of the engagement in the grooves 49 therein. As the studs 43 of the shoes 4|. engage in the openings 48 in the members 45, said shoes are supported from said members. Thus the shoes 4| and members 45 mentioned are confined in the opening 35 but due to the shape of the shoe shown in Fig. 9 are capable of a limited lateral relative movement in said opening sufiicient to provide a disengagement or separation between the rosette teeth 44-41 so that said shoes and members may be turned" relatively about the studs 43 as an axis.

The parts just mentioned are shown in their assembled position in Figs. 6, '7 and 8 and are held in this position by reason of the screw 5| which has been so turned as to cause the wedge block 58 to travel outwardly on the screw and in the grooves 49-49 of the members 45. In the movement of the wedge block toward the end bar 28, it moves the members 45-45 laterally outward and said members force the shoes 4|-4| outwardly. This tends to spread associated parts of the sides 38-38 of the back rest supporting member I9 into a gripping or clamping engagement with parts of th spider bars 21-21 with which they are engaged.

To adjust the member l9 either upwardly or downwardly, the screw 5| is turned to cause the wedge block 50 to move toward the bar 3|. The springs 52-52 then urge the members 45-45 inwardly so that sufficient looseness is present to release the gripping or clamping action the sides 38-38 had with the parts of the spider bars 21. This looseness need not be of such an extent as to provide a separation between the ro's'ette teeth 44-41 of the shoes 4| and members 45 respectively. By moving the supporting member in the proper direction and wherein it slides through the grooves 42-42 in the shoes 4|-4|, the said member may be disposed in the desired position. If it is desired also to adjust the forward or backward position of the back rest at this time, the screw 2| is actuated to provide that looseness of the parts as will permit separation of the rosette teeth 44-41 so that the back rest member |9 may be rocked forwardly or rearwardly about the axis as provided by the studs 43-43 of the shoes.

By turning the handle of the screw 5| in the other direction, the wedge block moves along said screw toward the bar 28. This forces the memb rs 45-45 outwardly and which in turn forces the shoes ll-4| outwardly to not only again engage the rosette teeth "-41 but to cause the sides 38--38 of the member I 8 to so grip or clamp against the bar parts 21 that the back rest member I9 is held in the desired adjusted position.

By means of the structure described, both the seat and the back rest may b readily adjusted to the desired position and securely held in that position.

While in describing the invention I have referred in detail to the form, arrangement and construction of the parts involved, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. A chair embodying therein a seat, means secured to the seat and definin an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a sho for each side part on the inner side thereof and having a longitudinal groove in its outer surface and in which the associated side part has sliding guided engagement, and means disposed between and having portions engaged with said shoes and supporting the same and including parts operative to impart a lateral outward movement to said shoes to force said side parts of said back rest supporting member into supporting engagement with the spaced sides of the first mentioned means. I

2. A chair embodying therein a seat, means secured to the seat and defining an opening havin laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a shoe for each sid part on the inner side thereof, said shoes and. said side parts having interengaging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, and means disposed between said shoes and supporting the same and including parts operative to impart a laterally outward movement to said shoes to force said side parts of said back rest supporting member into supporting engagement with the spaced sides of said opening.

3. A chair embodying therein a seat, means secured to the seat and defining an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said openin a shoe for each side part on the inner side thereof, said shoes and said side parts having interengaging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, laterally movable members disposed between said shoes, said members and said shoes having interengaging means for supporting said shoes in said openings, and means operative to impart 8, laterally outward movement to said last mentioned members to force the spaced parts of the back rest supporting member into supporting engage- .ment with the laterally spaced sides of said opening.

4. A chair embodying therein a seat, means secured to the seat and defining an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a shoe for each side part on the inner side thereof, said shoes and said parts having interengaging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, laterally movable members disposed between said shoes, said members and said shoes having interengaging means for supporting said shoes in said opening, a wedge disposed between said laterally movable members for movement forwardly and rearwardly of said opening, and manually operable means engaged with said wedge for imparting movement thereto, said wedge when moved in one direction in said opening causing lateral outward movement of said laterally movable member to impose a lateral outward thrust on said shoes to engage said side parts of the back rest supporting member in supporting engagement with the laterally spaced sides of said opening.

5. A chair embodying therein a seat, means secured to the seat and defining an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a shoe for each side part on the inner side thereof, said shoes and said side parts having interengaging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, means disposed between said shoes and supporting the same and including a forwardly and rearwardly movable wedge, and a screw member extending longitudinally of said opening and having a swivelled connection with parts of said first mentioned means and having a threaded engagement with said wedge for moving the same in either a forward or a rearward direction, said wedge when moved in one direction causing an outward thrust on said shoes to force the side parts of said back rest supporting member into supporting engagement with the spaced sides of the first mentioned means.

6. A chair embodying therein a seat, means secured to the seat and defining an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a shoe for each side part on the inner side thereof, said shoes and said side parts having interenga-ging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, laterally spaced members between said shoes, said side parts and said shoes having interengaging means for supporting said shoes in said opening, said members each having a front to rear channel therein and which channels face each other, a wedge engaged in the channels of both of said members, and a member extending longitudinally of said opening and swivelled in said first mentioned means and having a threaded engagement in said wedge for moving the same forwardly and rearwardly in said channels.

7. A chair embodying therein a seat, a supporting spider for said seat and disposed upon the underside thereof and made from a piece of strip metal bent to form parallel side bars, the rear end of said side bars extending beyond the rear edge of the ,seat and being connected by a cross piece, the front ends of said side bars being splayecl outwardly and formed to provide flat feet attached to the bottom of the seat, a cross bar between said side bars forwardly of said cross piece and coacting therewith and with parts of said side bars in forming an opening, means for securing a rear part of said seat to said cross bar, a back rest supporting member having a portion disposed in said Opening and including laterally spaced side parts engaged with said parts of the side bars of said spider, a shoe for each side part on the inner side thereof, said shoes and said side parts having interengaging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, laterally movable members disposed between said shoes, said members and said shoes having interengaging means supporting the shoes from said members, a wedge for imparting movement to said laterally movable members, and a, member extending through said cross piece and swivelled in the said cross bar of said spider respectively and having a threaded engagement with said wedge for causing the same to move said members outwardly.

8. A chair embodying therein a seat, means secured to the seat and defining an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a shoe for each side part on the inner side thereof, said shoes and said side parts having interengaging means whereby said parts are capable of a guid ed longitudinal movement relative to said shoes, members disposed between said shoes, means providing a pivotal supporting engagement between each shoe and associated member, and means operative, to impart a laterally outward movement to said members to force said shoes outwardly to cause said side parts of said back rest supporting member to supportingly engage the spaced sides of said first mentioned means.

9. A chair embodying therein a seat, means secured to the seat and defining an opening having laterally spaced sides, a back rest supporting member having a portion disposed in said opening and including laterally spaced side parts engaged with the sides of said opening, a shoe for each side part on the inner side thereof, said shoes and said side parts having interengaging means whereby said parts are capable of a guided longitudinal movement relative to said shoes, members disposed between said shoes, meansproviding a pivotal supporting engagement between each shoe and associated member, coacting means on the-opposed faces of said shoes andjthe associated membersrespectively for preventing relative rotation therebetween when said members are moved laterally outwardly, and means operative to impart a laterally outward movement to said members to force said shoes outwardly to cause said side parts of the back rest supporting member to supportinglyengage the spaced sides of the first mentioned means.

- ARTHUR E. JONES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Headley May 24, 

